ESR dating of aragonitic and calcitic corals , eolianite , calcrete , and corallineae from coral reefs in the South China Sea was applied to study of Quaternary reef geology . The ESR ages of calcitic corals correlate...ESR dating of aragonitic and calcitic corals , eolianite , calcrete , and corallineae from coral reefs in the South China Sea was applied to study of Quaternary reef geology . The ESR ages of calcitic corals correlated with the biostratigraphy , lithostratigraphy and geochemistry of Well Xi-Chen-1 and the oxygen-isotope stratigraphy of deep sea sediments, were reliable and up to 1.26 Ma. The selection of signals for dating and other related problems are discussed .展开更多
Ⅰ. INTRODUCTIONProfessor Pei Wen-zhong (W. C. Pei )discovered the first skull of Peking Man in December of 1929 at Zhoukoudian, 48 km from Beijing. But unfortunately, we do not know the burial age of this skull exact...Ⅰ. INTRODUCTIONProfessor Pei Wen-zhong (W. C. Pei )discovered the first skull of Peking Man in December of 1929 at Zhoukoudian, 48 km from Beijing. But unfortunately, we do not know the burial age of this skull exactly up to now.展开更多
在西藏札达盆地北缘阿伊拉日居山南北两麓及切割山脉的各沟谷中, 分布着4套第四纪冰川与冰水沉积物, 其冰川沉积物的电子自旋共振(ESR)测年结果分别为1 161～730 ka BP、 319～336 ka BP、 211 ka BP和105～15 ka BP. 测年结果表明, 在...在西藏札达盆地北缘阿伊拉日居山南北两麓及切割山脉的各沟谷中, 分布着4套第四纪冰川与冰水沉积物, 其冰川沉积物的电子自旋共振(ESR)测年结果分别为1 161～730 ka BP、 319～336 ka BP、 211 ka BP和105～15 ka BP. 测年结果表明, 在札达盆地北缘阿伊拉日居山南麓所发生的4次冰川作用, 其形成时期分别为早更新世晚期、中更新世中晚期、中更新世晚期和末次冰期.展开更多
The Gongga Mountain is the largest area of modern glaciation in the Hengduan Mountains and,with a summit elevation of 7556 m,is the highest mountain on the eastern margin of the Tibetan Plateau.During the Quaternary g...The Gongga Mountain is the largest area of modern glaciation in the Hengduan Mountains and,with a summit elevation of 7556 m,is the highest mountain on the eastern margin of the Tibetan Plateau.During the Quaternary glacial-interglacial cycles the Gongga Mountain was extensively and repeatedly glaciated,and glacial landforms and outwash deposits from multiple glaciations are well-preserved in valleys,in basins,and on piedmonts.To constrain the glacial chronology of the eastern slope of Gongga Mountain,sample sites were selected based on the distribution and weathering of glacial tills,relationships among glacial deposits,and soil development on moraines.Dating of the tills and glaciofluvial deposits was undertaken with electron spin resonance(ESR) and optically stimulated luminescence(OSL).The ages of the glacial deposits can be divided into four clusters:2.2±0.5,11.9±0.6,35.9±2.7-58.0±6.3 and 119.2±15.9-194.2±32.8 ka.Five glacial advances in this region have been identified,which are equivalent in age to the Little Ice Age(LIA),Neoglaciation,marine oxygen isotope stage(MIS) 2,mid-MIS3,and MIS6.The largest local last glacial maximum(LGML) occurred on Gongga Mountain during mid-MIS3,characterized by a cold-humid climate,rather than the global Last Glacial Maximum(LGMG) of MIS2.The Gongga,Nanmenguangou(NMGG) and Yajiageng Glaciations occurred during the late part of the last glacial cycle,the middle of the last glacial cycle and the penultimate glacial cycle,respectively.On the basis of geomorphological,sedimentological,and compositional characteristics,landforms of the Moxi Platform and terraces can be grouped by facies and geochronology.In combination with the dating results,this analysis indicates the basal part of the Moxi Platform between Xinxin and the Moxi Hotel is correlative with the till of the Nanguanmen Glaciation(mid-MIS3).This basal unit has occasional lenses of glaciofluvial sandy gravel and lacustrine sediments.The remainder of the Moxi Platform and the terraces beside the platform are glaciofluvial deposits occasionally mixed with debris flow deposits and range in age from MIS3 to Holocene.展开更多
Southeastern Tibet is one of the most glaciated regions on the Tibetan Plateau both at present and during the Quaternary. Numerical dating of glacial deposits has allowed the establishment of a provisional chronology ...Southeastern Tibet is one of the most glaciated regions on the Tibetan Plateau both at present and during the Quaternary. Numerical dating of glacial deposits has allowed the establishment of a provisional chronology of Quaternary glacial fluctuations in this region, with the oldest glaciation(Guxiang Glaciation) occurring in marine oxygen isotope stage 6(MIS-6).During our recent field investigations, a morphostratigraphically older lateral moraine than that of the Guxiang Glaciation has been first identified, which is ~500–600 m above the Guxiang Glaciation moraine and discontinuously preserved on valley shoulders in the Bodui Zangbo River valley, eastern Nyainqêntanglha Range in southeastern Tibet. Considering the moraine is best preserved at Nitong Village, here we name the glacier advance which deposited the moraine as "Nitong Glaciation". Using electron spin resonance(ESR) technique, we dated the Nitong Glaciation moraine to 506.3±60.4 ka. Taking into account the age error and climatic conditions, we consider it most likely that the Nitong Glaciation occurred during MIS-12, although it might had happened sometime earlier.展开更多
文摘ESR dating of aragonitic and calcitic corals , eolianite , calcrete , and corallineae from coral reefs in the South China Sea was applied to study of Quaternary reef geology . The ESR ages of calcitic corals correlated with the biostratigraphy , lithostratigraphy and geochemistry of Well Xi-Chen-1 and the oxygen-isotope stratigraphy of deep sea sediments, were reliable and up to 1.26 Ma. The selection of signals for dating and other related problems are discussed .
文摘Ⅰ. INTRODUCTIONProfessor Pei Wen-zhong (W. C. Pei )discovered the first skull of Peking Man in December of 1929 at Zhoukoudian, 48 km from Beijing. But unfortunately, we do not know the burial age of this skull exactly up to now.
文摘在西藏札达盆地北缘阿伊拉日居山南北两麓及切割山脉的各沟谷中, 分布着4套第四纪冰川与冰水沉积物, 其冰川沉积物的电子自旋共振(ESR)测年结果分别为1 161～730 ka BP、 319～336 ka BP、 211 ka BP和105～15 ka BP. 测年结果表明, 在札达盆地北缘阿伊拉日居山南麓所发生的4次冰川作用, 其形成时期分别为早更新世晚期、中更新世中晚期、中更新世晚期和末次冰期.
基金supported by National Natural Science Foundation of China(Grant No.41171063)Fundamental Research Funds for the Central Universities(Grant No.LZUJBKY-2010-114)+1 种基金Foundation of State Key Laboratory of Cryospheric Sciences,Cold and Arid Regions Environment and Engineering Research Institute,Chinese Academy Sciences(Grant No.SKLCS2011-03)the Program of Ministry of Science and Technology of China(Grant No.2006FY110200)
文摘The Gongga Mountain is the largest area of modern glaciation in the Hengduan Mountains and,with a summit elevation of 7556 m,is the highest mountain on the eastern margin of the Tibetan Plateau.During the Quaternary glacial-interglacial cycles the Gongga Mountain was extensively and repeatedly glaciated,and glacial landforms and outwash deposits from multiple glaciations are well-preserved in valleys,in basins,and on piedmonts.To constrain the glacial chronology of the eastern slope of Gongga Mountain,sample sites were selected based on the distribution and weathering of glacial tills,relationships among glacial deposits,and soil development on moraines.Dating of the tills and glaciofluvial deposits was undertaken with electron spin resonance(ESR) and optically stimulated luminescence(OSL).The ages of the glacial deposits can be divided into four clusters:2.2±0.5,11.9±0.6,35.9±2.7-58.0±6.3 and 119.2±15.9-194.2±32.8 ka.Five glacial advances in this region have been identified,which are equivalent in age to the Little Ice Age(LIA),Neoglaciation,marine oxygen isotope stage(MIS) 2,mid-MIS3,and MIS6.The largest local last glacial maximum(LGML) occurred on Gongga Mountain during mid-MIS3,characterized by a cold-humid climate,rather than the global Last Glacial Maximum(LGMG) of MIS2.The Gongga,Nanmenguangou(NMGG) and Yajiageng Glaciations occurred during the late part of the last glacial cycle,the middle of the last glacial cycle and the penultimate glacial cycle,respectively.On the basis of geomorphological,sedimentological,and compositional characteristics,landforms of the Moxi Platform and terraces can be grouped by facies and geochronology.In combination with the dating results,this analysis indicates the basal part of the Moxi Platform between Xinxin and the Moxi Hotel is correlative with the till of the Nanguanmen Glaciation(mid-MIS3).This basal unit has occasional lenses of glaciofluvial sandy gravel and lacustrine sediments.The remainder of the Moxi Platform and the terraces beside the platform are glaciofluvial deposits occasionally mixed with debris flow deposits and range in age from MIS3 to Holocene.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41771065, 42071088, 41271077 and 41371080)。
文摘Southeastern Tibet is one of the most glaciated regions on the Tibetan Plateau both at present and during the Quaternary. Numerical dating of glacial deposits has allowed the establishment of a provisional chronology of Quaternary glacial fluctuations in this region, with the oldest glaciation(Guxiang Glaciation) occurring in marine oxygen isotope stage 6(MIS-6).During our recent field investigations, a morphostratigraphically older lateral moraine than that of the Guxiang Glaciation has been first identified, which is ~500–600 m above the Guxiang Glaciation moraine and discontinuously preserved on valley shoulders in the Bodui Zangbo River valley, eastern Nyainqêntanglha Range in southeastern Tibet. Considering the moraine is best preserved at Nitong Village, here we name the glacier advance which deposited the moraine as "Nitong Glaciation". Using electron spin resonance(ESR) technique, we dated the Nitong Glaciation moraine to 506.3±60.4 ka. Taking into account the age error and climatic conditions, we consider it most likely that the Nitong Glaciation occurred during MIS-12, although it might had happened sometime earlier.
